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CVE-2025-59287: Microsoft Windows Server Update Service (WSUS) Deserialization of Untrusted Data Vulnerability

CVE-2025-59287 is rated critical with a CVSS v3.1 base score of 9.8 and affects Microsoft Windows. Per its scoring, it can be exploited over the network, without authentication, without any user interaction. The scored impact on confidentiality, integrity and availability is the highest available. CISA added it to its Known Exploited Vulnerabilities catalog on 2025-10-24, which means exploitation in the wild has been observed.

Vulnerability description

Deserialization of untrusted data in Windows Server Update Service allows an unauthorized attacker to execute code over a network.

Severity breakdown

CVSS v3.1 9.8: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack vector: Network. Exploitable remotely over the network, with no need for local or physical access.
Attack complexity: Low. No special conditions; the attack can be repeated reliably.
Privileges required: None. No account or prior access is needed.
User interaction: None. No action from any user is needed.
Scope: Unchanged. Impact stays within the vulnerable component.
Confidentiality impact: High. Total loss of confidentiality; sensitive data can be fully disclosed.
Integrity impact: High. Total loss of integrity; data or system state can be fully modified.
Availability impact: High. Total loss of availability; the component can be shut down.

Underlying weakness

CWE-502: Deserialization of Untrusted Data

The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.

Affected products

Microsoft Windows Server 2012: all versions listed by NVD; r2
Microsoft Windows Server 2016: before 10.0.14393.8524
Microsoft Windows Server 2019: before 10.0.17763.7922
Microsoft Windows Server 2022: before 10.0.20348.4297
Microsoft Windows Server 2022 23h2: before 10.0.25398.1916
Microsoft Windows Server 2025: before 10.0.26100.6905